Cell-binding peptides conjugated to poly(ethylene glycol) promote neural cell aggregation

We have developed a method for promoting cell aggregation with bifunctional macromolecules synthesized by coupling cell-binding peptides to an inert, water-soluble polymer. The peptides Arg-Gly-Asp (RGD) and Tyr-Ile-Gly-Ser-Arg (YIGSR) were conjugated through their amino termini to both ends of linear poly(ethylene glycol) (PEG), producing bifunctional hybrid polymers: RGD-PEG-RGD and YIGSR-PEG-YIGSR. RGD-PEG-RGD promoted aggregation of mechanically-dissociated fetal brain cells, pheochromocytoma cells (PC12), and neuroblastoma cells maintained in rotation culture at 37 degrees C. Enhanced aggregation was noticeable within 10 minutes and became more pronounced over the next several hours: after 7-9 hours, the mean aggregate volume was up to 10 times larger than the mean volume produced in suspensions containing unmodified PEG. Similar results were obtained with YIGSR-PEG-YIGSR and PC12 cells. Enhancement in aggregation correlated with the ability of soluble RGD or YIGSR to inhibit cell adhesion to surfaces coated with laminin or fibronectin. This method for promoting aggregation may be useful for large scale culture of anchorage dependent cells, eliminating the need for microcarriers. In addition, aggregates formed by this method may be suitable for use in artificial organs or as cell transplants for tissue regeneration.

Antiparasitic and antiproliferative effects of indoleamine 2,3-dioxygenase enzyme expression in human fibroblasts

Studies were carried out to evaluate the proposed role of indoleamine 2,3-dioxygenase (INDO) induction in the antimicrobial and antiproliferative effects of gamma interferon (IFN-gamma) in human fibroblasts. The INDO cDNA coding region was cloned in the pMEP4 expression vector, containing the metallothionein (MTII) promoter in the sense (+ve) or the antisense (-ve) orientation. Human fibroblasts (GM637) stably transfected with the sense construct expressed INDO activity after treatment with CdCl2 or ZnSO4, but cells transfected with the antisense construct did not. The growth of Chlamydia psittaci was strongly inhibited in INDO +ve cells but not in INDO -ve cells after treatment with Cd2+ or Zn2+. The inhibition correlated with the level of INDO activity induced and could be reversed by the addition of excess tryptophan to the medium. The growth of Toxoplasma gondii was also strongly inhibited in INDO +ve cells but not in INDO -ve cells after treatment with Cd2+. Expression of Cd(2+)-induced INDO activity also inhibited thymidine incorporation and led to cytotoxicity in INDO +ve cells but not in INDO -ve cells. Thus, the induction of INDO activity by IFN-gamma may be an important factor in the antimicrobial and antiproliferative effects of IFN-gamma in human fibroblasts.

Modulation of lipopolysaccharide-mediated cytokine secretions by retinoic Acid

Human primary bone marrow cells secret various cytokines upon stimulation with lipopolysaccharide (LPS). This study demonstrated that LPS-mediated cytokine secretion can be affected by all-trans retinoic acid (t-RA). t-RA stimulated LPS-mediated granulocyte colony stimulating factor (G-CSF) secretion over two-fold and inhibited both LPS-mediated granulocyte-macrophage CSF (GM-CSF) and tumor necrosis factor alpha (TNFalpha) secretion by as much as 50%. The stimulation of t-RA on LPS-mediated G-CSF secretion was dose-dependent and was observed at t-RA concentration of as low as 10(-10) M. Some other retinoids were also as effective as t-RA, whereas other steroids were either less or not effective or inhibitory on LPS-mediated G-CSF secretion. Further experiments indicated that interleukin 1 (IL-1), one of the mediators of LPS activity, also synergized with t-RA to stimulate G-CSF secretion. These observations suggest that there is a convergence of IL-1 and t-RA signal transduction pathways in G-CSF release by bone marrow cells.

Molecular cloning of a novel receptor tyrosine kinase, tif, highly expressed in human ovary and testis

Using a combination of polymerase chain reaction and conventional cDNA library screening approaches, we have cloned and characterized a putative receptor tyrosine kinase termed tif. The extracellular domain of tif has an immunoglobulin-like loop and a fibronectin type III structure. The intracellular domain contains a tyrosine kinase domain. Compared with ryk, a ubiquitously expressed receptor tyrosine kinase, tif expression is tissue-specific with human ovary and testis containing the highest amount of tif mRNA. Many other tested human tissues such as heart, liver, pancreas and thymus do not contain detectable levels of tif mRNA. The molecular cloning and characterization of tif cDNA will facilitate the identification of a potential ligand(s) for the putative receptor and the study of its biological role.

[The effect of Tripterygium wilfordii monomers T4,T7,T15 and Triptolide on rat nuclear protein]

Rat epididymal sperms were collected after 7 weeks of treatment with Tripterygium wilfordii monomers T4,T7,T15 and triptolide. Total nuclear basic protein (TNBP) were extracted from sperm nuclei isolated by sonication. The relative proportions of histones and protamine were determined by scanning microdensitometry following electrophoresis of TNBP in polyacrylamide gels. It was found that the content of TNBP was reduced while the total histone/protamine ratios were increased following treatment, indicating a marked decrease of protamine levels as compared with the control group. These results suggest that the interruption of nuclear protein transition of spermatids induced by T4,T7,T15 and triptolide might lead to infertility.

Enhanced gel mobility shift assay for DNA-binding factors

Gel mobility shift assays are commonly used to study DNA-binding factors involved in the regulation of constitutive, tissue-specific, and inducible genes. We found that addition of 3-[(3-cholamidopropyl)dimethylammonio]-propanesulfonate (Chaps, a zwitterionic detergent) at relatively high concentration (2.5% or more) to DNA-binding reactions for four different factors (AP-1, SP1, GATA-1, and interferon alpha-regulated factor ISGF3) assayed in cell extracts greatly enhanced the signal for DNA-protein complexes (up to about 20-fold). The amplified signal for DNA-protein complexes so obtained was (at least in part) due to increased binding efficiency, as revealed by greatly reduced amounts of the free probes in the gels. The binding specificity, however, was not compromised. The fact that DNA-protein complex formation with four different factors was stimulated by Chaps suggests that the enhancing effect of Chaps may be more general and not limited to certain types of DNA-binding factors. The results provide the basis for a highly sensitive assay for DNA-binding factors, which may be useful in several types of studies on such factors. Among other detergents tested, Chapso (another zwitterionic detergent), NP-40, and octylglucopyranoside (nonionic detergents) were found also to enhance the complex formation as tested for AP-1 binding, whereas sodium cholate and deoxycholate showed strong inhibition.

Downregulation of GATA-1 expression during phorbol myristate acetate-induced megakaryocytic differentiation of human erythroleukemia cells

Phorbol myristate acetate (PMA) induces the expression of megakaryocyte and/or platelet proteins during terminal differentiation of human erythroleukemia (HEL) cells. However, it is not established whether megakaryocytic differentiation is accompanied by the downregulation of the major erythroid transcription factor GATA-1 and the concomitant loss of the erythrocytic phenotype. Studies of the molecular mechanism of PMA-induced differentiation in HEL cells showed that when HEL cells are treated with PMA, they dramatically decrease the expression of the erythroid-specific gene glycophorin A at the mRNA level but apparently not at the steady-state protein level. In addition, a gel mobility shift assay was used to demonstrate that GATA-1, a major erythroid transcription factor normally present at high levels in HEL cells is downregulated after treatment with PMA. In contrast, the DNA-binding activities of transcription factors AP-1 and SP-1 are upregulated by PMA treatment of HEL cells. Furthermore, Northern blot analysis shows that PMA also downregulates the steady-state level of GATA-1 mRNA in HEL cells. The coordinated negative regulation of glycophorin A mRNA and GATA-1 expression after PMA treatment suggests that downregulation of GATA-1 expression may be partially responsible for the loss of the erythroid phenotype during megakaryocytic differentiation. The reported data also suggest that GATA-1 activity may not be essential for obtaining megakaryocytic phenotype during terminal differentiation in HEL cells.

[Structural protein of hemorrhagic fever renal syndrome virus in uric fusion cells in hemorrhagic fever renal syndrome]

The efoliative cells in the urine of 21 hemorrhagic fever patients with renal syndrome (HFRS) were examined with Swiss blue staining. Fusion cells were found in the urine of 18 HFRS patients. The quantity of fusion cells was closely related to the severity of patients' condition and renal damage. Specific antigen of HFRS virus (HFRSV) was found immunohistochemically in all fusion cells. Specific monoclonal antibodies (McAb) of membrane protein and nucleocapsid protein from HFRSV were used for analyzing antigen in fusion cells. The positive rate of membrane protein antigen was 72.2%. Nucleocapsid protein was not found in all fusion cells. The above results suggested that the forming of fusion cells in the urine of HFRS patients is related membrane protein of HFRSV.

An international comparison of case definition of severe adverse cutaneous reactions to medicines

There is substantial intercountry variation in the proportion of cases of toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) which are attributed to specific drugs. This study was undertaken to determine whether these differences might reflect biases in diagnosis of these conditions. A total of 138 reactions in 5 countries originally diagnosed as TEN or SJS were coded on to standardised forms. A single observer blind to the original diagnosis assessed each case according to specified criteria. This observer's diagnoses were compared with the original diagnoses. Overall, 111 of the 138 cases had information adequate for assessment. The blinded observer agreed with the diagnosis for 61% of cases where the original diagnosis was TEN and 58% of cases where the original diagnosis was SJS. There was no significant difference in rates of agreement when reactions attributed to sulphonamide antibiotics were compared with reactions attributed to other drugs. There were substantial and significant differences in percentage agreement between the blinded observer's diagnosis and the original diagnoses between countries. The lowest rates of agreement between the blinded observer and the original reports occurred in the US. Our results illustrate the difficulty in comparing reaction rates based on spontaneous reports between countries where the systems for gathering such reports vary. This illustrates the need for a minimum quantity of standard data and precise definitions of reactions if spontaneous reports of adverse reactions are to provide useful information about severe adverse skin reactions associated with drugs.

Anatomical mapping of functional activation in stereotactic coordinate space

Numerous applications have been reported for the stereotactic mapping of focal changes in cerebral blood flow during sensory and cognitive activation as measured with positron emission tomography (PET) subtraction images. Since these images lack significant anatomical information, analysis of these kinds of data has been restricted to an automated search for peaks in the PET subtraction dataset and localization of the peak coordinates within a standardized stereotactic atlas. This method is designed to identify isolated foci with dimensions smaller than the image resolution. Details of activation patterns that may extend over finite distances, following the underlying anatomical structures, will not be apparent. We describe the combined mapping into stereotactic coordinate space of magnetic resonance imaging (MRI) and PET information from each of a set of subjects such that the major features of the activation pattern, particularly extended tracts of increased blood flow, can be immediately assessed within their true anatomical context as opposed to that presumed using a standard atlas alone. Near areas of high anatomical variability, e.g., central sulcus, or of sharp curvature, e.g., frontal and temporal poles, this information can be essential to the localization of a focus to the correct gyrus or for the rejection of extracerebral peaks. It also allows for the removal from further analysis of data from cognitively-normal subjects with abnormal anatomy such as enlarged ventricles. In patients with neuropathology, e.g., Alzheimer's disease, arteriovenous malformation, stroke, or neoplasm, the use of correlated MRI is mandatory for correct localization of functional activation.

Analysis of interferon-gamma resistant mutants that are possibly defective in their signaling mechanism

Our previous observations indicated that mutants partially resistant to IFN-gamma cytotoxicity were defective in the induction of indoleamine 2,3-dioxygenase, (IDO). Two mutants highly resistant to IFN-gamma were isolated following a second round of mutagenesis. The resistance to IFN-gamma was inversely correlated with the inducibility of IDO in these mutants. Moreover, several other IFN-gamma responsive genes, including those encoding 2-5A synthetase, GTP cyclohydrolase and HLA-DR alpha, were also differentially altered in their expression upon INF-gamma treatment. IFN-gamma receptor gene expression was not changed nor was the binding of the receptor to IFN-gamma. Southern blot analysis failed to reveal any significant abnormality in the IDO gene structure in these mutants. We therefore suggest that these mutants are defective in the IFN-gamma signaling pathway and will be useful in further analysis of the biochemical mechanism of IFN-gamma activated gene expression in target cells.

[The effect of three kinds of thyroid hormone preparations on serum thyroid hormone and TSH in primary hypothyroidism]

Thirty-eight cases of primary hypothyroidism were treated prospectively with three kinds of thyroid hormone preparations, including Levothyroxine, L-triiodothyronine and dry thyroid preparation. A protocol of different dosages with same biologic effects was followed: 100 micrograms Levothyroxine approximately 40-60 mg dry thyroid preparation approximately 30-40 micrograms L-triiodothyronine. During drug replacement treatment, the change serum T3 and TSH is more sensitive than that of serum T4 and reverse T3. Both of serum T3 and T4 can directly inhibit the secretion of pituitary TSH, but serum T4 is more closely related to TSH than is T3. In judging the overdose, the level of serum T4 is a superior indicator to the level of T3. The best time to take thyroid hormone preparations is at bedtime.

[Microsurgery to treat lesions in or near the eyeball wall]

Four sub-retinal cysticerci and 12 cases of nonmagnetic intraocular foreign bodies near the eyeball wall were first localized with indirect ophthalmoscopy and then removed successfully under surgical microscopy. Three layers, ie white sclera, black supra-choroid pigment and light brown choroidal tissue with white vascular pattern were encountered before reaching the sub-retinal larval. The ischemic appearance of the choroid probably was caused by compression of the larval underneath it. Intraocular foreign bodies usually appeared in the wound accompanied by liquified vitreous as soon as the incision was made. If intraocular inflammation exist, foreign body can be found within the pus or dense exudates.

Regulation of indoleamine 2,3-dioxygenase gene expression in human fibroblasts by interferon-gamma. Upstream control region discriminates between interferon-gamma and interferon-alpha

The interferon (IFN)-gamma-mediated induction of indoleamine 2,3-dioxygenase (IDO) enzyme, which converts tryptophan into N-formylkynurenine, has been implicated in the inhibition of intracellular pathogens, e.g. Toxoplasma gondii and Chlamydia psittaci, and in the antiproliferative effect of IFN-gamma on tumor cells. The IDO activity is induced strongly in many cell types by IFN-gamma but rather poorly by IFN-alpha or -beta. A genomic DNA clone containing part of the transcribed region of the IDO gene and approximately 13 kilobases (kb) of the 5'-upstream DNA sequence was isolated and analyzed. An approximately 1.4-kb fragment of this clone, containing 329 nucleotides of the transcribed sequence and approximately 1.1 kb of the 5'-upstream sequence, when ligated to chloramphenicol acetyltransferase (CAT) structural gene made its expression inducible by IFN-gamma, but this construct responded poorly, if at all, to IFN-alpha 2. Deletion constructs derived from this plasmid narrowed down the IFN-gamma-responsive region to a 151-nucleotide segment (-495/-344) which also contained a 14-nucleotide sequence (GGTTTCAGTTTTCC) highly homologous to the IFN(alpha)-stimulated response element (ISRE) that has been found so far in all cellular genes inducible with IFN-alpha or -beta. Expression of CAT activity was stimulated by IFN-gamma more effectively than by IFN-alpha 2 when a 155-nucleotide fragment (-495/-340) containing the 151-nucleotide segment required for IFN-gamma response was inserted before herpes simplex virus thymidine kinase promoter linked to CAT structural gene. The results indicate that despite the presence of an ISRE, the control region of the IDO gene can distinguish between IFN-gamma and IFN-alpha. This may account for the differential activation of IDO gene expression by IFN-gamma as against IFN-alpha or -beta in intact cells, and suggests that the response of ISRE to IFN-alpha or -beta may be governed by other features in the upstream control region of this gene.

Molecular cloning, sequencing and expression of human interferon-gamma-inducible indoleamine 2,3-dioxygenase cDNA

The antiproliferative action of human interferon (HuIFN)-gamma on human cells and the inhibition of intracellular pathogens, e.g. Toxoplasma gondii and Chlamydia psittaci, is at least in part due to an induction of indoleamine 2,3-dioxygenase (IDO) enzyme which degrades tryptophan, an essential amino acid. A cDNA clone (called C42) was isolated from a cDNA library made from poly(A)+ RNA obtained from HuIFN-gamma-treated human fibroblasts. Its nucleotide sequence revealed an open reading frame coding for a polypeptide of 403 amino acids, but no homology with any known gene in GenBank database was found. Evidence was obtained indicating that this cDNA codes for IDO: (i) Hybrid selected C42 specific poly(A)+ RNA from IFN-gamma-treated human cells coded for a polypeptide in vitro of approximately 42 kD (reported size of IDO, approximately 40 kD) which was immunoprecipitated by monoclonal anti-IDO antibody but not by a control antibody; and (ii) transfection of human fibroblasts with an expression plasmid containing C42 cDNA transcribed from chicken beta-actin promoter led to constitutive expression of C42 specific RNA as well as IDO activity. This cDNA clone will be useful in studying the role of IDO in the biological effects of IFN-gamma, and the regulation of IDO gene by IFN-gamma.

[Expression of MG7 corresponding antigen in gastric polyp and its relation to gastric carcinoma]

Forty-nine cases of gastric polyp (GP) were studied by histologic classification and immunohistochemical localization of monoclonal antibody MG 7 against gastric carcinoma. There were 12 cases (24.5%) of inflammatory polyp; 19 cases (38.8%) of hyperplastic polyp and 18 cases (36.7%) of adenomatous polyp. 3 cases (6.1%) of GP were malignant, among which 2 (11.1%) were adenomatous polyp and 1 (5.3%) was hyperplastic polyp. Seventeen cases (34.7%) of GP were MG 7 positive by ABC method, including 7 (36.8%) of hyperplastic polyp and 10 (55.5%) of adenomatous polyp. The inflammatory polyps were negative, and all of the cases with malignancy were strongly positive. The results showed that both GP and gastric carcinoma express MG 7 related antigen. These suggest that adenomatous polyp and hyperplastic polyp are closely related with gastric carcinogenesis.

Respiratory dysfunction in patients with common variable hypogammaglobulinemia

Patients with common variable hypogammaglobulinemia (CVH) are susceptible to recurrent respiratory infections. We studied the prevalence and severity of respiratory dysfunction in 32 patients with CVH by measuring routine pulmonary function tests (PFT) and interpreting chest radiographs using a quantitative score system. Pulmonary symptoms were determined by patient interview and standard questionnaire. The mean age of 29 living patients was 28 +/- 2.2 yr; there were 22 males and 10 females. The mean age at diagnosis was 17.3 +/- 2.4 yr. Sinopulmonary symptoms were present in all 32 patients and included chronic sinusitis, otitis, bronchitis, recurrent pneumonia, and bronchiectasis. Complete PFT in 25 patients revealed restrictive, obstructive, and normal patterns in 10, 6, and 9 patients, respectively. Nine patients had dyspnea on exertion. Recent chest radiographs in 32 patients showed evidence of recurrent pulmonary infection, including air trapping, linear markings, and pleural abnormalities. Panlobular emphysema, documented in one case at autopsy, was suggested in 5 other patients by the presence of lower lobe bullous lesions and marked lower lobe hyperlucency on chest radiographs. The forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) had remained stable in 19 adults (18 receiving adequate immunoglobulin replacement therapy) for 6.9 +/- 0.7 yr. The expected increase of the FEV1 and FVC with growth was normal in 6 of 8 children (all 8 receiving adequate therapy). Chest radiograph scores deteriorated only slightly from 20.3 +/- 0.6 to 18.4 +/- 0.8 (25 = normal) during the 6.9 +/- 0.7 yr in 30 patients (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Soluble peptidoglycan fragments stimulate antibacterial protein synthesis by fat body from larvae of Manduca sexta

Both hemocytes and fat body from larvae of Manduca sexta, which have been injected with inducers of antibacterial protein synthesis, contain immunoreactive lysozyme. However, fat body is a richer source and has been demonstrated to synthesize and release lysozyme and cecropin-like peptides (bactericidins) in vitro. Fat body secretion of lysozyme and bactericidins is stimulated by addition of soluble peptidoglycan fragments to culture medium. The rate of lysozyme secretion by fat body varies as a function of peptidoglycan inducer concentration. These data are consistent with the hypothesis that, in vivo, bacteria must be phagocytized and partially degraded (processed) by hemocytes to generate a signal (peptidoglycan) that subsequently induces antibacterial protein synthesis by fat body.

Plasma testosterone, high density lipoprotein cholesterol and other lipoprotein fractions

High density lipoprotein (HDL) cholesterol levels are strongly related to risk of heart attack. Identification of determinants of high density lipoprotein cholesterol may provide important information concerning the cause of heart disease. The relation between one possible determinant, testosterone, and high density lipoprotein cholesterol and other lipoprotein fractions was evaluated in 247 middle-aged men. The results indicate that testosterone levels (both free and total) were positively correlated with high density lipoprotein cholesterol (r = +0.24, p less than 0.01) and negatively correlated with triglycerides and very low density lipoprotein cholesterol. The association between testosterone and high density lipoprotein cholesterol could not be explained by intake of alcohol, obesity, age, smoking or physical activity. Furthermore, the relation of testosterone to HDL cholesterol was independent of the relation of testosterone to very low density lipoprotein (VLDL) cholesterol or triglycerides.

The relationship between alcohol consumption, liver enzymes and high-density lipoprotein cholesterol

High-density lipoprotein (HDL) cholesterol concentrations are inversely related to risk of heart attack. Alcohol consumption is a primary factor related to increased HDL concentrations. We investigated HDL cholesterol before and after cessation of high alcohol consumption in alcoholics. Men admitted to an alcohol detoxification hospital had a mean HDL cholesterol level of 85 mg/dl, which is almost twice that found in the general population. After 4 days of treatment, HDL cholesterol levels decreased an average of 12.5 mg/dl. The decrease was directly correlated with the initial HDL cholesterol levels and inversely correlated with the change in triglyceride levels. Alcoholics who abstained for at least 1 month had HDL cholesterol concentrations similar to those of the general population. The increased HDL cholesterol levels in the alcoholics were highly correlated with liver enzyme concentrations, especially SGOT. The results suggest that alcohol increases HDL cholesterol concentrations through hepatic microsomal enzyme induction.